Rivetless nut plate and fastener

ABSTRACT

A nut plate and nut are disclosed wherein the nut plate secures the nut to a mounting plate. The nut plate includes a projection which is adapted to be received by a hole in the mounting plate to prevent relative rotation between the nut plate and the mounting plate. The nut is provided with a flange about a periphery of the nut with a portion of the nut being received within a tubular portion of the nut plate and within an opening in the mounting plate.

This application is a continuation, of application Ser. No. 204,285,filed 6/9/88 now U.S. Pat. No. 4,919,578.

BACKGROUND AND SUMMARY OF THE PRESENT INVENTION

The present invention relates generally to fasteners and moreparticularly relates to fasteners having nut plates which are to besecurely attached to a mounting plate.

Anchor nut fasteners are known wherein a nut plate is attached to amounting plate. Typically, a threaded nut is retained by the nut platein a floating manner in order to facilitate insertion of a bolt into thenut. Rotation of the nut relative to the nut plate is prevented bysidewalls of the nut plate which engage a portion of the nut.

In such fasteners, it is necessary to mount the nut plate onto themounting plate securely and to prevent rotation of the nut platerelative to the mounting plate. In a known arrangement, the nut platemay be secured to the mounting plate by way of rivets which are providedon either side of a centrally located nut. Such an arrangement isundesirable, however, because of the need to drill three holes in themounting plate including two holes for the rivets and one hole whichprovides access to the threaded nut for a threaded bolt. Especiallywhere a significant number of such fasteners are to be used, the need toprovide three relatively accurately spaced holes in the mounting plateresults in a considerable expenditure of time and labor. Moreover, thethree closely spaced holes may in some cases unduly weaken the mountingplate creating the potential for cracks and damage to the mounting plate

In another known arrangement for securing a nut plate to a mountingplate, rotation of the nut plate is intended to be prevented by knurlingwhich is provided on a tubular portion of an attaching sleeve. Theattaching sleeve has a flange at one end and the tubular portion isinserted through the nut plate and into a hole which has been providedin the mounting plate. The tubular portion is then deformed to retainthe nut plate on the mounting plate and the knurling is intended tfrictionally engage the sidewalls of the hole in the mounting plate.However, to provide the knurling on the tubular portion requires anexpenditure of time and effort. Moreover, if the engagement between theknurled tubular portion and the sidewalls of the hole is not adequate orif excessive torque is applied to the nut, an unacceptable rotation ofthe nut plate may result.

In those arrangements where the nut plate is secured by rivets,replacement of a defective nut plate is relatively time consuming anddifficult due to the need to remove the rivets.

Accordingly, it is an object of the present invention to provide a nutplate for either fixed or floating nuts which may be secured to amounting plate without the use of rivets.

Yet another object of the present invention is to provide a nut plate inwhich relative rotation between the nut plate and a mounting plate onwhich the nut plate is fastened is prevented in an economical andefficient manner.

Still another object of the present invention is to provide a nut platewherein the potential to unduly weaken the member on which the nut plateis fastened is reduced.

Yet still another object of the present invention is to provide animproved fastener including a nut plate and nut according to the presentinvention.

A still further object of the present invention is to provide animproved fastener including a nut plate and nut wherein assembly anddisassembly is facilitated and the reliability of the fastener and themounting plate is increased.

These and other objects are accomplished by a nut plate and fasteneraccording to the present invention wherein the nut plate includes agenerally flat portion which is provided with means to securely receivea nut. Means are also provided to secure the nut plate to a mountingplate with the means including a tubular portion which extends into ahole which has been provided in the mounting plate. The nut plate alsoincludes a torque pin or projection which is spaced away from thetubular portion and which is adapted to be received within a torque pinhole or recess in the mounting plate. The projection prevents a relativerotation of the nut plate and the mounting plate.

The fastener according to the present invention comprises a nut plateincluding a generally flat portion which is provided with means tosecurely receive a nut. The nut includes a flange or skirt which isprovided circumferentially about a longitudinal axis of the nut. Atubular portion of the nut extends beyond the flange and is adapted tobe received within a tubular portion of the nut plate. The tubularportion of the nut plate is adapted to be deformed, swaged, spun orcrimped so as to securely fasten the nut plate to a mounting plate. Thenut plate also includes a torque pin or projection which is spaced awayfrom the tubular portion and which is adapted to be received within atorque pin hole or recess in the mounting plate. The projection preventsa relative rotation of the nut plate and the member.

BRIEF DESCRIPTION OF THE DRAWINGS

Preferred embodiments of the present invention will be described ingreater detail with reference to the accompanying drawings, wherein likemembers bear like reference numerals and wherein:

FIG. 1 is a perspective view of a nut plate and nut according to thepresent invention;

FIG. 2 is a perspective view of the nut plate of FIG. 1;

FIG. 3 is a perspective view of the nut of FIG. 1;

FIG. 4 is an top view of the nut plate of FIG. 2 prior to assembly withthe nut of FIG. 3;

FIG. 5 is a side view of the nut plate of FIG. 4;

FIG. 6 is an top view of the nut of FIG. 3;

FIG. 7 is a side view of the nut of FIG. 6;

FIG. 8 is a side view in partial cross section of a mounting plate whichhas been prepared to receive the nut plate and nut of FIG. 1;.

FIG. 9 is a side view in partial cross section of the mounting plate ofFIG. 8 during the installation of the nut plate and nut of FIG. 1.

FIG. 10 is a side view in partial cross section of the nut plate and nutof FIG. 1 installed on the mounting plate of FIG. 8; and

FIG. 11 is a side view in partial cross section of a nut and nut plateaccording to the present invention wherein the nut and nut plate areintegral.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

With reference to FIG. 1, a fastener 10 according to the presentinvention includes a nut plate 12 and a nut 14 which is partiallYreceived within the nut plate 12. The nut may be any of a variety ofscrew fasteners and may be provided with any desired suitable,conventional features such as a locking feature. The nut 14 and the nutplate 12 are preferably of metal, for example, stainless steel.

With reference also to FIG. 2, the nut plate 12 includes a relativelyflat portion 16 which is provided with deformable sidewalls 18. Thesidewalls 18 each have a recessed portion 20, see FIG. 4, having asmooth configuration 21 corresponding to the nut 14.

The nut 14 includes a tubular portion 22 which has been provided withinternal threads so as to receive a fastener member such as a threadedbolt (not shown). The tubular portion 22 is open at at least one end 23and is preferably closed at the other end 24 to form a dome nut. Ifdesired, the nut may be open at both ends. The type of threads and thedimensions of the nut and threads may be varied as desired.

A flange 26 or skirt is provided about the tubular portion 22 of thenut. The flange 26 includes two parallel straight edges 28 which areprovided on either side of the flange 26. The flange 26 is dimensionedso as to be floatingly received by the sidewalls 18 of the nut plate 12when the sidewalls 18 have been deformed around the flange 26. Ifdesired, the nut 22 could be rigidly fastened to the nut plate 12 bysecurely gripping the edges 28 of the flange 26 between the flat portion16 and the sidewalls 18. Alternatively, the nut could be integrallyformed with the nut plate, see FIG. 11.

The flange 26 is provided about the tubular portion of the nut 22 spacedaway from either end of the nut. In this way, a part of the tubularportion including the open end 23 of the nut is provided on one side ofthe flange 26. Another part of the tubular portion of the nut isprovided on the other side of the flange 26. When the nut 14 is receivedwithin the nut plate 12, the part of the tubular portion 22 includingthe open end 23 of the nut is received within the tubular portion 17 ofthe nut plate. If desired, an 0-ring seal 15 may be provided between thenut 14 and the nut plate 12 between the open end 23 and the tubularportion 17.

The nut plate 12 also includes a projection 30 or tab which extendsgenerally perpendicularly to the flat portion 16 of the nut plate 12.The projection 30 is formed integrally with the nut plate 12 andpreferably is provided on the periphery of the flat portion 16 midwaybetween the sidewalls 18.

During assembly, with reference to FIG. 8, a member or mounting plate 32on which the nut plate and nut according to the present invention are tobe mounted is provided with a stepped bore 34. The stepped bore 34includes a first portion 36 which is dimensioned so as to receive thetubular portion 17 of the nut plate 12. The stepped bore also includes asecond portion 38 which has a slightly larger diameter. The stepped bore34 may be provided in the member 32 using a step drill bit 40 in asuitable, conventional manner.

The member 32 is also provided with a torque pin hole 42 or recess whichmay be blind or open and which is spaced away from the stepped bore 34by a distance corresponding to the distance between the projection 30and the tubular portion 17 of the nut plate 12. The torque pin hole 42is provided on the side of the member 32 having the first portion 36 ofthe stepped bore 34. The torque pin hole 42 preferably does not extendcompletely through the member 32 so as to minimize the effect of therecess on the member 32. If desired, however, the torque pin hole couldof course extend completely through the member 32 (not shown). If thetorque pin hole extends completely through the member 32, it may bedesirable to provide a plug 50 or sealing cap (see FIG. 1) in the torquepin hole adjacent to the projection 30 to close an exposed end of thehole.

With reference now to FIG. 9, the nut plate 12 is positioned adjacent tothe mounting plate 32 with the tubular portion 17 of the nut plateinserted into the stepped bore 34. Preferably, the end of the tubularportion 17 of the nut plate extends slightly beyond the end of the firstportion 36 of the stepped bore 34 but not beyond the second portion 3 ofthe stepped bore 34. The end 19 of the tubular portion 17 of the nutplate is tapered so as to facilitate the deformation of the end of thetubular portion by a tool member 44. The nut 14 is floatingly retainedby the sidewalls 18 of the nut plate 12 and the tubular portion 22 ofthe nut 12 extends into the stepped bore 34 of the member 32. The phrase"floatingly" is meant to include that the nut is arranged to moveradially in a direction which is transverse to the longitudinal axis ofthe nut plate's tubular portion 22, as shown, for example, in FIG. 10.Preferably, the tubular portion 22 of the nut 12 does not extend beyondthe first portion 36 of the stepped bore 34. The projection 30 extendsinto the torque pin hole 42 of the member 32. The torque pin hole 42 issized so as to snugly receive the projection without obstructing themating of the nut plate 12 with the mounting plate 32.

To secure the tubular portion 17 of the nut plate 12 to the mountingplate 32, a threaded portion 46 or holding screw of the tool 44 isengaged with the threaded portion of the nut 14. A suitably configuredend or swaging die 48 of the tool 44 is then brought into engagementwith the end 19 of the tubular portion of the nut plate 12 so as toswage or deform the end 19 into the second portion 38 of the steppedbore 34. After deformation, the end 19 of the tubular portion 17preferably is smoothly curved as shown at 21, (see FIG. 10). As desired,the end of the nut plate may be swaged, spun or crimped against themounting plate.

If desired, the stepped bore 34 may be replaced with a countersunk bore(not shown) wherein the countersunk portion of the bore corresponds tothe second portion 38 of the stepped bore 34. The end 19 of the tubularportion of the nut plate 12 may then be simply flared of deformedoutwardly so as to securely mount the nut plate onto the mounting plate32.

By arranging the nut 14 so that the open end 23 of the nut extends intothe tubular portion 17 of the nut plate (and in turn into the firstportion of the stepped bore 34 or the countersunk bore), the ease ofassembly and the reliability of the fastener are increased. While thenut is being floatingly secured to the nut plate 12, the engagement ofthe open end 23 of the nut in the tubular portion 17 of the nut platefacilitate the proper positioning of the nut with respect to the nutplate. Moreover, since the threaded portion of the nut extends into themember 32, a more compact arrangement is provided for a fastener havingthe same extent of threads.

By providing the O-ring between the nut and the nut plate, the fasteneraccording to the present invention may eliminate the need for a rubberboot and a corresponding bonding operation for the fastener. Moreover,since the alignment of the nut on the nut plate is ensured and since thethreaded portion of the nut is provided in close proximity to thesurface of the member 32 where the threaded bolt is to be inserted, theengagement of the threaded bolt with the nut is facilitated.

The principles, preferred embodiments and modes of operation of thepresent invention have been described in the foregoing specification.However, the invention which is intended to be protected is not to beconstrued as limited to the particular embodiments disclosed Further,the embodiments described herein are to be regarded as illustrativerather than restrictive. For example, an entirely satisfactoryarrangement for certain end use applications could involve a floatingnut fastener, wherein the open end 23 of the nut 14 is positionedsubstantially coplanar with the surface of the flange 26 that faces themember 32. Variations and changes may be made by others withoutdeparting from the spirit of the present invention and it is expresslyintended that all such variations and changes which fall within thespirit and scope of the present invention as defined in the claims, beembraced thereby.

What is claimed is:
 1. A nut plate for use with a threaded fastener, thenut plate comprising:a generally flat portion having a passagewaytherethrough, said generally flat portion defining a plane; means forsecuring said nut plate to a mounting plate, said means for securingincluding a tubular portion which extends generally perpendicularly withrespect to said flat portion, said tubular portion being substantiallyimmovable in the plane defined by said generally flat portion after saidtubular portion extends generally perpendicularly with respect to saidflat portion; means for loosely securing a threaded fastener to said nutplate adjacent said passageway whereby a threaded member may be receivedby said threaded fastener, said threaded fastener being loosely securedto said nut plate after said nut plate is secured to said mountingplate; and means for preventing relative rotation between said nut plateand said mounting plate, said means for preventing relative rotationincluding a projection which extends generally perpendicularly withrespect to said flat portion, said projection extending on the same sideof said flat portion as the tubular portion of said means for securing,said projection being substantially immovable in the plane defined bysaid generally flat portion.
 2. The nut plate of claim 1, wherein saidmeans for loosely securing a threaded fastener to said nut plateincludes first and second sidewalls of said flat portion which areadapted to be deformed in a direction opposite to said projection, saidsidewalls floatingly retaining said threaded fastener.
 3. The nut plateof claim 2, wherein said projection is provided midway between saidfirst and second sidewalls and at a periphery of said flat portion. 4.The nut plate of claim 1, wherein said threaded fastener is floatinglyretained by said means for loosely securing a threaded fastener.
 5. Thenut plate of claim 1, wherein said projection is integral with saidgenerally flat portion.
 6. The nut plate of claim 4, wherein saidprojection is integral with said generally flat portion.
 7. The nutplate of claim 3, wherein said projection is integral with saidgenerally flat portion.
 8. A nut plate and nut adapted to be mounted ona mounting plate having an opening therethrough, comprising:a nut platecomprising a generally flat portion having a passageway therethrough,said generally flat portion defining a plane, said nut plate furthercomprising means for securing said nut plate to a mounting member, saidmeans for securing including a tubular portion which extends generallyperpendicularly with respect to said flat portion, said tubular portionbeing substantially immovable in the plane defined by said generallyflat portion after said tubular portion extends generallyperpendicularly with respect to said flat portion, means for looselysecuring a nut to said nut plate adjacent said passageway whereby athreaded member may be received by said nut, said nut being looselysecured to said nut plate after said nut plate is secured to saidmounting plate, means for preventing relative rotation between said nutplate and said mounting plate, said means for preventing relativerotation including a projection which extends generally perpendicularlywith respect to said flat portion, said projection being provided on thesame side of said flat portion as the tubular portion of said means forsecuring; and a nut, said nut having a tubular portion which isthreaded.
 9. The nut plate and nut of claim 8, wherein the nut isfloatingly retained by the means for loosely securing a nut.
 10. Afastener which is adapted to be mounted on a mounting plate having anopening therethrough and a hole adjacent the opening, comprising:a nutincluding a tubular portion having an internal thread; and a nut plateincluding means for loosely securing the nut to the nut plate, said nutbeing loosely secured to said nut plate after said nut plate is securedto said mounting plate, said nut plate defining a plane, means forsecuring the nut plate to the mounting plate and means for preventingrotation of said nut plate relative to said mounting plate, said meansfor securing the nut plate to the mounting plate including a tubularportion which extends generally perpendicularly with respect to saidflat portion and which is substantially immovable in the plane definedby the nut plate after said tubular portion extends generallyperpendicularly with respect to said flat portion, said means forpreventing rotation including a projection which is adapted to bereceived by said hole of said mounting plate, said projection beingsubstantially immovable in the plane defined by the nut plate.
 11. Thefastener of claim 10, wherein said tubular portion is formed integrallyin the nut plate and is adapted to extend into the opening of themounting plate, whereby said tubular portion may be deformed at one endto secure the ut plate to the mounting plate.
 12. The fastener of claim10, wherein the nut is floatingly secured to said nut plate by saidmeans for loosely securing the nut.